U.S. patent number 7,011,092 [Application Number 10/729,507] was granted by the patent office on 2006-03-14 for portable hypoxic apparatus.
This patent grant is currently assigned to AirSep Corporation. Invention is credited to Norman R. McCombs, Michael R. Valvo.
United States Patent |
7,011,092 |
McCombs , et al. |
March 14, 2006 |
Portable hypoxic apparatus
Abstract
Hypoxic delivery apparatus producing from ambient air a product
gas having a lower levels of oxygen concentration and delivering
the product gas to a user of the apparatus in pulse doses.
Alternatively, the apparatus may include a selector for alternately
delivering either a nitrogen enriched gas or an oxygen enriched gas
to the user.
Inventors: |
McCombs; Norman R. (Tonawanda,
NY), Valvo; Michael R. (East Aurora, NY) |
Assignee: |
AirSep Corporation (Buffalo,
NY)
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Family
ID: |
32595097 |
Appl.
No.: |
10/729,507 |
Filed: |
December 5, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040134493 A1 |
Jul 15, 2004 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60432913 |
Dec 12, 2002 |
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Current U.S.
Class: |
128/205.12;
128/205.11; 128/205.27 |
Current CPC
Class: |
A61M
16/0045 (20130101); A61M 16/101 (20140204); A61M
16/12 (20130101); A63B 2213/006 (20130101); B01D
53/047 (20130101); B01D 2256/10 (20130101); B01D
2259/40009 (20130101); B01D 2259/402 (20130101); B01D
2259/4533 (20130101); B01D 2259/4541 (20130101); A61M
16/1055 (20130101); A61M 16/107 (20140204) |
Current International
Class: |
A62B
19/00 (20060101) |
Field of
Search: |
;128/202.12,205.11,205.12,205.27,205.28,205.26 ;482/13 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
NCBI website: Abstract of Journal of Applied Physiology article
entitled "Living high-training low: effect of moderate-altitude
acclimatization with low-altitude training on performance", by
Levine et al., issued Jul. 1997, 1 page. cited by other .
NCBI website: Abstract of Journal of Applied Physiology article
entitled "Individual variation in response to altitude training" by
Chapman et al., issued Oct. 1998, 1 page. cited by other .
NCBI website: Abstract of International Journal of Sports Medicine
article entitled "Training high-living low: changes of aerobic
performance and muscle structure with training at simulated
altitude", by Geiser et al., issued Nov. 2001, 1 page. cited by
other .
NCBI website: Abstract of Advances in Experimental Medicine and
Biology article entitled "Hypoxia training for sea-level
performance. Training high-living low", by Hoppeler et al., issued
2001, 1 page. cited by other .
NCBI website: Abstract of International Journal of Sports Medicine
article entitled " Altitude and hypoxia training--a short review",
by Boning, issued Nov. 1997, 1 page. cited by other .
NCBI website: Abstract of Sports Medicine article entitled "Current
trends in altitude training", by Wilber, issued 2001, 2 pages.
cited by other .
NCBI website: Abstract of Bulletin of Experimental Biology and
Medicine article entitled "Adaption to hypoxia as a method of
treatment and prevention of gastroduodenal mucosa lesions", by
Agadzbanyan et al., issued Sep. 2001, 1 page. cited by other .
NCBI website: Abstract of High Altitude Medicine & Biology
article entitled "Intermittent hypoxia research in the former
Soviet Union and the commonwealth of independent States: history
and review of the concept and selected applications", by
Serebrovskaya, issued Sep. 2002, 2 pages. cited by other .
NCBI website: Abstract of Aviation, Space, and Environmental
Medicine article entitled Improving athletic performance: is
altitude residence or altitude training helpful?, by Fulco et al.,
issued Feb. 2000, 1 page. cited by other .
NCBI website:Abstract of High Altitude Medicine & Biology
article entitled "Intermittent hypoxic training: fact and fancy",
by Levine, issued Summer 2002, 1 page. cited by other .
NCBI website: Abstract of Journal of Applied Physiology article
entitled "Living high-training low, altitude training improves sea
level performance in male and female elite runners", by
Stray-Gundersen et al., issued Sep. 2001, 1 page. cited by other
.
Schoene R.B. Hypoxic ventilatory response and exercise ventilation
at sea level and high altitude. Chapter In: High Altitude and Man,
Editor J.B. West, Waberly Press Inc., 1984, 11 pages. cited by
other .
Baker, A. & Hopkins, W.G. (1998). Altitude training for
sea-level competition In: Sportscience Training & Technology,
Internet Society for Sport Science.
http://sportsci.org/traintech/altitude/wgh.html, 14 pages. cited by
other .
Journal of Applied Physiology article entitled "Cardiovascular
response to hypoxia after endurance training at altitude and sea
level and after detraining" by Katayama et al., issued Apr. 2000,
15 pages. cited by other .
Abstract of Journal of Applied Physiology article entitled
"Live-high, train low increases the hypoxic ventilatory response of
well-trained endurance athletes", by Townsend et al., issued Jun.
2002, 2 pages. cited by other .
GO2Altitude, Health and Fitness Equipment for Intermittent Hypoxic
Training website, 2000, 4 pages. cited by other .
Mar., 2002 News Relaese--AirSep's LifeStyle Portable Oxyge
Concentrator Enters World Marketplace, 3 pages. cited by other
.
NCBI website: Abstract of High Altitude Medicine & Biology
article entitled "Physiological effects of intermittent hypoxia",
by Powell et al., issued Summer 2000, 1 page. cited by
other.
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Primary Examiner: Patel; Mital
Attorney, Agent or Firm: Hiscock & Barclay, LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from a Provisional Patent
Application Ser. No. 60/432,913, filed Dec. 12, 2002.
Claims
What is claimed is:
1. A compact and portable hypoxic gas delivery apparatus by
producing from ambient air a product gas having lower levels of
oxygen concentration and delivering the product gas to a user of
the apparatus, the apparatus comprising a pressure swing adsorption
unit having at least one adsorber bed to receive ambient air and
adsorb the nitrogen or the oxygen from the ambient air to produce
both a nitrogen enriched gas and an oxygen enriched gas, and
control means for delivering the nitrogen enriched gas in a pulse
dose to a user for a selectable predetermined period of time and
actuated upon initial inhalation by the user, the control means
further comprising means for increasing or decreasing the effective
flow rate of the nitrogen enriched gas by increasing or decreasing
the activation time during each inhalation cycle.
2. The apparatus according to claim 1 and further comprising means
for selectively switching the pressure swing adsorption unit to
deliver in the pulse dose to the user the oxygen enriched gas
instead of the nitrogen enriched gas.
3. The apparatus according to claim 1 in which the pressure swing
adsorption unit comprises two adsorber beds alternately producing
the enriched gases, and further comprising valve means for
controlling the flow of air and gases alternately through the
beds.
4. The apparatus according to claim 1 and further comprising means
for adjusting the enrichment of the nitrogen in the nitrogen
enriched gas to simulate various geographic altitudes.
5. The apparatus according to claim 1 and further comprising means
for adjusting the enrichment of the nitrogen in the nitrogen
enriched gas to produce selectively different concentrations of
oxygen and nitrogen in the nitrogen enriched gas.
6. The apparatus according to claim 1 in which the pressure swing
adsorption unit comprises three adsorber beds alternately producing
the enriched gases.
7. The apparatus according to claim 1 and further comprising means
for powering the apparatus from any one of three sources including
a rechargeable battery pack, an AC adapter for connection to an AC
outlet, and a DC adapter for connection to the power system of a
vehicle.
8. A compact and portable hypoxic gas delivery apparatus by
producing from ambient air a product gas having a lower levels of
oxygen concentration and delivering the product gas to a user of
the apparatus, the apparatus comprising a pressure swing adsorption
unit having at least one adsorber bed to receive ambient air and
adsorb the nitrogen or oxygen from the ambient air to produce both
a nitrogen enriched gas and an oxygen enriched gas, and means for
selectively delivering either the nitrogen enriched gas or the
oxygen enriched gas to a user during inhalation by the user.
9. The apparatus according to claim 8 and further comprising means
control means for delivering the selected enriched gas in pulse
doses to the user at selectable rates and actuated upon initial
inhalation by the user.
10. The apparatus according to claim 9 in which the control means
actuating the flow of delivered gas upon initial inhalation further
comprises means for increasing or decreasing the effective flow
rate of the selected enriched gas by increasing or decreasing the
activation time during each inhalation cycle.
11. The apparatus according to claim 8 in which the pressure swing
adsorption unit comprises two adsorber beds alternately producing
the enriched gases, and further comprising valve means for
controlling the flow of air and gases alternately through the
beds.
12. The apparatus according to claim 8 and further comprising means
for adjusting the enrichment of the nitrogen in the nitrogen
enriched gas to simulate various geographic altitudes.
13. The apparatus according to claim 8 and further comprising means
for adjusting the enrichment of the nitrogen in the nitrogen
enriched gas to produce selectively different concentrations of
oxygen and nitrogen in the nitrogen enriched gas.
14. The apparatus according to claim 8 in which the pressure swing
adsorption unit comprises three adsorber beds alternately producing
the enriched gases.
Description
FIELD OF THE INVENTION
This invention relates generally to apparatus for delivering
reduced oxygen levels of a breathable gas for physical training
purposes and/or for therapeutic use, by pressure swing adsorption
("PSA").
BACKGROUND OF THE INVENTION
The general benefits and value of conducting physical training in a
hypoxic (oxygen-deprived or lower oxygen concentration than in
normal air) environment are documented. For example, research in
"Intermittent Hypoxic Training (IHT)" ranging from basic research
(physiology, biochemistry, cell biology, etc.) to practical
applications (athletic training, therapeutic applications) has been
reported in a number of recognized, reputable journals appearing in
the data base of the National Library of Medicine, including High
Altitude Medicine and Biology; Anesthesiology; Chest, Bulletin of
Experimental Biology and Medicine, Sports Medicine; International
Journal of Sports Medicine; and Journal of Applied Physiology.
A significant portion of the research has dealt with the use of IHT
for athletic training and conditioning, one studied training
approach being the so called "living high--training low" approach.
This approach involves having an athlete "live" in a hypoxic
environment and undergo physical training in a normoxic
environment. In multiple cited studies, this approach seems to have
produced measurable improvement in athletic performance and, in
some studies, measurable changes in physiological and
biochemical/hematological parameters. While multiple authors state
that more controlled research is needed to determine the total
scope and value of the applicability of this type of training for
athletes, the literature supports the basic idea as valid and
useful.
From an athletic perspective, individuals who are trained under
hypoxic conditions are expected to develop significantly improved
physical endurance responses. These improved physical endurance
responses are said to include both greater physical endurance at
normal (low) altitudes (below 1800 meters above sea level), in such
activities as distance running and swimming, and improved endurance
at high altitudes (above 1800 meters) in such activities as
mountain climbing.
Research is reported to have shown, for example, that hypoxic
training resulting in acclimatization to a low oxygen environment
can lead not only to increased endurance in that environment, but
also lead to increased physiological and biochemical adaptation and
defense mechanisms, including perhaps increased erythropoetin
production (with possible increase in red blood cell production);
improved immune system function; adrenal stimulation;
cardiovascular adaptation (e.g., reduced peripheral resistance,
increased vasodilation, and increased capillary density); decreased
mean arterial blood pressure and decreased heart rate; and
respiratory adaptation (e.g., increased pulmonary capacity,
increased hypoxic ventilatory response, increased total lung
capacity, increased vital lung capacity, and increased minute
ventilation).
Controlled studies appear to have shown that athletes who have
naturally occurring or congenital blunted ventilatory drives (i.e.,
less sensitivity and natural response to increased carbon dioxide
and decreased oxygen levels in the blood) experience less dyspnea
(i.e., subjective difficulty or distress in breathing or shortness
of breath) and lower work of breathing at given levels of work,
which may make exercise and athletic performance both more
comfortable and more efficient. Such a blunted ventilatory drive
may be one factor which predisposes certain individuals to
outstanding athletic performance. It is postulated in the art that
the equivalent of a natural blunted ventilatory drive can be
achieved through physical training in a hypoxic environment,
including the resulting benefits to endurance, athletic
performance, and comfort and efficiency of exercise and athletic
performance.
Studies also are reported to have shown that the changes produced
by physical training in a hypoxic environment will decrease, even
with continued physical training, in a normal-oxygen environment.
The implication is that sustained hypoxic training is necessary to
retain the benefits of hypoxic training.
While there apparently are significantly fewer references regarding
therapeutic uses of IHT, several abstracts located cover the
therapeutic uses of IHT, including the use of IHT to treat lesions
of the gastroduodenal mucosa (ulcers) and the use of IHT to prevent
refractory hypoxemia during chest surgery. Although we have no
direct evidence to support any such benefits, it has also been said
that hypoxic training may possibly provide increased resistance to
ionizing radiation; improved resistance to poisons and venoms;
improved resistance to viral infections; decreased recovery time
after surgery; increased (improved) exercise till exhaustion (ETE)
time; protection of the brain from oxidative stress; increased
positive benefits from adaptive sleep; and improvements in a number
of classes of diseases (e.g., ischemic heart disease, hypertension,
bronchitis and asthma, gastric and duodenal ulcer disease, liver
and pancreatic disease including diabetes, motor diseases and
gynecological diseases.
In summary, studies known in the art appear to have established
that physical training in a hypoxic (lower-than-normal oxygen
concentration) environment can produce beneficial changes in
biochemical and physiological functioning of the body, can produce
beneficial improvement in and resistance to certain disease
processes, and can produce beneficial improvement in athletic
performance and endurance.
The many potential benefits of, and the wide range of potential
uses and applications of, hypoxic environment physical training
point to the value of developing hypoxic environment training
methods and devices which are practical, cost effective, portable,
and flexible.
The oldest and most direct method of hypoxic environment training
is to have individuals or teams train at high altitudes, e.g., 1500
meters and higher. The cost, inconvenience, and danger from the
environment, along with the lack of flexibility for the "high-low"
approach (other than by moving up and/or down a mountain) make this
an impractical method of hypoxic environment training in most
cases. More accepted methods of hypoxic environment training now
include sealed chambers or tents, and breathing masks used with
pressurized tanks of low concentration oxygen or with pressure
swing adsorption apparatus to produce a hypoxic gas. These methods
allow flexibility in the composition of the breathing gasses
delivered to trainees (adjusting the composition with more nitrogen
and less oxygen for more hypoxic conditions) based primarily on the
time that the user is in the hypoxic environment or breathes the
hypoxic gas.
The isolation chamber and the tent both have the drawback of lack
of mobility; the user must be stationary, within the sealed chamber
or tent, and must travel to the location of the chamber or tent for
each hypoxic training session. On the other hand, the use of a face
mask, to which a regulated flow of hypoxic breathing gas is
delivered, provides the user with some mobility during use, but
still requires that the user be relatively stationary because of
the relative size of the equipment. This forms the basis for the
"high-low" approach to intermittent hypoxic training by exposure to
hypoxic treatment for fixed periods of time, e.g., every 30 minutes
for a prescribed amount of time within a predetermined training
regimen. Thus, more vigorous motion or required exercise
necessarily must stop or be significantly curtailed while the user
is inhaling the hypoxic gases.
SUMMARY OF THE INVENTION
The present invention offers a very practical alternative to the
known methods of intermittent hypoxic training by our invention of
a highly portable apparatus that can enable the user to train both
to the intermittent hypoxic training technique and to a continuous
hypoxic training technique as with training at a high geographic
altitude. Our portable system has great potential for use by
athletes and possibly as well for therapeutic treatment as and when
hypoxic therapeutic techniques become proven regimens for medical
purposes.
The present invention comprises functional features which make it
superior to other methods used for hypoxic training. The present
invention is a gas concentration apparatus which separates gas
mixtures by pressure swing adsorption (PSA), and more particularly
for production of a product gas for breathing having a desired
concentration and flow rate of a particular gas. Apparatus
according to the present invention can be adjusted to produce
particular nitrogen/oxygen gas ratios to simulate various
geographic altitudes, and in one embodiment can also be switched
immediately to produce a high concentration of oxygen if the user
senses a level of exhaustion that requires an immediate "shot" of
oxygen.
Moreover, the apparatus according to our invention is sufficiently
light and portable to avoid the necessity of stopping physical
activity while breathing the hypoxic gas. It can be fabricated in a
small enough in size and light enough in weight to allow continuous
use while the user is able to move about relatively unrestricted by
the equipment. This is a great advantage which allows the user to
train in all conceivable locations while performing physical tasks
which relate directly to the athletic activity for which the user
is in training. For example, a trainee could transport the present
invention to a gym and use it continuously on a treadmill, a
stair-climber, and/or any other training apparatus. For therapeutic
medical uses, the present invention is very well suited to in-home,
as well as clinic and hospital use, due to its portability and
flexibility. It is even conceivable that the present invention can
find a place in all manner of sports and athletic training, pilot
training, diver training, and astronaut training.
Yet another distinct advantage of the present invention is its
ability to be adjusted to deliver breathing gas to the user during
only a portion of inspiration. It is known in the art that only the
gas inhaled at the initial or effective stage of inhalation or
inspiration is that which is usefully absorbed by the lungs. The
remaining inhaled gas in the latter stage of inhalation is usually
exhaled before it can be absorbed by the lungs. The kinetics of
oxygen-carbon dioxide exchange in the pulmonary alveoli, along with
the volume flow characteristics of human pulmonary inspiration,
result in this phenomenon.
The present invention is adaptively flexible, so that it can
actuate the flow of gas upon initial inhalation and terminate the
flow of gas after the effective stage, say 190 ms after initial
inhalation. It is thus possible to increase or decrease the
effective flow rate of breathing the hypoxic gas by increasing or
decreasing the activation time during each inhalation cycle. By
delivering breathing gas only during the effective (initial) stage
of inspiration, the present invention greatly increases the
efficiency of the breathing gas delivered, resulting in requiring
less breathing gas stored in tanks and/or produced by the
adsorption process, allowing the apparatus to be smaller and
lighter in weight (significantly more portable), and giving greater
longevity to the apparatus and all its components, due to the need
to produce less breathing gas for any given training session or
therapeutic session while producing effective results.
Because of the great flexibility of the present invention, it can
be adjusted to produce many concentrations of breathing gas. One
advantage of this is to permit advancing a user through
progressively greater degrees of hypoxia by producing breathing
gasses with lower and lower percentages of oxygen during a series
of training sessions.
Although the present invention can be used with a face mask with
openings that allow inhalation of ambient air through openings in
the mask, our preference is the use of a nasal-prong delivery
device or cannula. A cannula minimizes encumbrance and interference
by the device, while allowing for freer execution of training
activities by the user.
We believe that use of the present invention will produce more
efficient and faster results from all types of hypoxic training
sessions, as well as allow efficient maintenance training sessions,
e.g., to preserve the positive effects of the hypoxic training once
achieved by the trainee. Because of the relative size, it can be
used both in intermittent and continuous hypoxic training. We
believe it may also be used for therapeutic purposes, for example,
to enable persons with relatively weakened breathing abilities to
strengthen their lung capacities.
Our invention uses a proven principle of pressure swing adsorption,
or PSA. PSA apparatus and methods are described in the prior art.
See U.S. Pat. Nos. 3,564,816; 3,636,679; 3,717,974; 4,802,899;
5,531,807 and 5,871,564, among others. For example, a pressure
swing adsorption apparatus may include one or more adsorbers, each
having a fixed sieve bed of adsorbent material to fractionate at
least one constituent gas from a gaseous mixture by adsorption into
the bed, when the gaseous mixture from a feed stream is
sequentially directed through the adsorbers in a co-current
direction. While one adsorber performs adsorption, another adsorber
is simultaneously purged of its adsorbed constituent gas by part of
the product gas that is withdrawn from the first or producing
adsorber and directed through the other adsorber in a
counter-current direction. Once the other adsorber is purged, the
feed stream at a preset time is then directed to the other adsorber
in the co-current direction, so that the other adsorber performs
adsorption. The first adsorber then is purged either
simultaneously, or in another timed sequence if there are more than
two adsorbers, all of which is understood by those skilled in the
art.
The invention uses a two or three bed PSA together with an
integrated pulse dose delivery device or gas flow controller (GFC),
as will be explained, with selectively variable effective
oxygen/nitrogen breathing ratios to simulate different geographic
altitudes. A further embodiment of the invention is selectable to
deliver the reduced oxygen gas, or if desired by the user during or
after physical training to switch to high oxygen levels to
facilitate physical recovery.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the invention will become more
apparent from a reading of the following description in connection
with the accompanying drawing of a preferred embodiment of the
invention, in which:
FIG. 1 is a schematic illustration of a combined PSA/GFC apparatus
according to the invention to deliver a breathable gas with reduced
oxygen levels;
FIG. 2 is a flow chart illustrating a sequence of operation of the
PSA/GFC apparatus;
FIGS. 3 and 3A are schematic illustrations of a second embodiment
of the invention, showing a combined PSA/GFC apparatus according to
the invention that is selectable to deliver either a breathable gas
with reduced oxygen levels or a breathable gas with a high
concentration of oxygen; and
FIGS. 4 and 5 are flow charts illustrating the sequences of
operation of the PSA/GFC apparatus according to the second
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to FIG. 1 of the drawing and in accordance with the
present invention, there is shown a preferred embodiment, generally
indicated as A, of a combined pressure swing adsorption apparatus
and gas flow device, or PSA/GFC, used for fractionating at least
one component, in this case oxygen, from ambient air, by pressure
swing adsorption to produce a product gas with reduced oxygen
concentration, and for delivering the product gas at specific and
variable intervals upon demand by a user. The general operating
principles of pressure swing adsorption are well known and are
disclosed, for example, in commonly assigned U.S. Pat. Nos.
4,802,899, 5,531,807 and 5,871,564, the entire disclosures of which
are incorporated by reference herein. Although these patents
describe apparatus to produce product gases with higher oxygen
concentrations, the principles of operation are similar, except
that an oxygen adsorbent sieve material such as a known carbon
molecular sieve material or synthetic zeolite is used in the
embodiment of FIG. 1. In addition, conservation by pulse dosing of
the supply of a product gas such as oxygen from a pressurized tank,
in order to increase the useful life of the stored oxygen, also is
generally known and is disclosed, for example in U.S. Pat. No.
6,427,690, issued Aug. 6, 2002 and entitled Combined Oxygen
Regulator and Conservation Device, the entire disclosure of which
is incorporated by reference herein. A combination apparatus for
the delivery of higher concentrations of oxygen is described in
co-pending U.S. Provisional Application No. 60/353,563 filed Jan.
31, 2002 and its corresponding non-provisional application Ser. No.
10/354,275, filed Jan. 30, 2003, both entitled Portable Oxygen
Concentrator, the entire disclosures of which also are incorporated
by reference herein.
With reference to FIG. 1, ambient air is supplied to the PSA/GFC
apparatus A through a filtered intake and an intake resonator 1 to
decrease the noise from the intake of the ambient air feed stream.
The feed stream continues from resonator 1 and is moved from its
outlet by a feed air compressor 2 and heat exchanger 4
alternatively to left and right adsorbers through feed valves 6 and
8 respectively.
When the feed stream alternatively enters the inlets at the lower
ends of the adsorbers in a co-current direction, the respective
adsorber fractionates the feed stream into the desired
concentration of product gas. The adsorbent material used for the
beds, if used to separate nitrogen from the ambient air, may be a
sodium alumina silicate or other known adsorber material having
equivalent properties.
In the embodiment of FIG. 1, unlike the apparatus described in the
above mentioned PSA patents, oxygen rather than nitrogen is
separated from the ambient air by using a known oxygen adsorbent
sieve material such as a synthetic zeolite and is discharged to the
atmosphere, whereas the balance of the ambient air forms product
gas with a higher concentration of nitrogen for delivery to the
user through the PSA/GFC in measured pulse doses.
The substantial or usable portion of the nitrogen enriched product
gas generated by the ambient air flowing in the co-current
direction sequentially in each one of the absorbers is directed
through the respective outlet (at the upper ends) and check valve
13, 14 of the corresponding adsorber to a product manifold and then
to a mixing tank 15. The balance of the product gas generated by
each adsorber is timed to be diverted through a purge orifice 12
and a properly timed equalization valve 11 and an optional flow
restrictor (not shown) to flow through the other adsorber in the
counter-current direction from the respective outlet and to the
respective inlet of the other adsorber to purge the adsorbed,
primarily oxygen, gases. The counter-current product gas and purged
gases then are discharged to the atmosphere from the adsorbers
through properly timed waste valves 7, 9, tubing and a sound
absorbing muffler 10.
The mixing tank 15 serves as a reservoir to equalize the enriched
nitrogen product gas before delivery to the user through an
apparatus outlet in the pulse dose mode, a piston-type pressure
control regulator 16 to regulate the product gas pressure to be
delivered to the user, a bacteria filter (not shown), and the gas
flow controller or GFC 17 including the electronic control circuit
and a flow control solenoid operated valve using the principles as
disclosed in U.S. Pat. No. 6,427,690.
FIG. 2 illustrates a flow diagram of the flow of gases by the timed
sequence of the operating valves in which FA and FB are the feed
valves 6 and 8 of the left or A bed and the right or B bed,
respectively, WA and WB are the waste valves 7 and 9, respectively,
and EQ is the equalization valve 11. The operational steps are
timed in seconds, whereas the illustrated changes in pressure are
measured as PSIG.
According to the invention, delivery of the PSA generated nitrogen
enriched gas from the mixing tank 15 to the user is controlled by
the GFC as will now be described.
As is noted above, the most effective use of inhaled gas occurs at
the onset of inhalation. For example, various devices have been
constructed to deliver oxygen from pressurized oxygen tanks only
when inhalation is first sensed by the devices and only during the
initial stage of the inhalation cycle. We have taken advantage of
that well known principle to devise a much more compact and
efficient PSA apparatus for the enriched nitrogen to deliver the
enriched nitrogen at the initial stage of inhalation. As is
disclosed in U.S. Pat. No. 6,427,690 and in co-pending applications
Ser. No. 60/353,563 and No. 10/354,275, a low pressure sensor will
detect a drop in pressure as sensed by inhalation of a user through
a conventional cannula connected to the apparatus outlet by which
the nitrogen enriched gas is delivered to the user. When the
pressure sensor detects the pressure drop, the transducer circuitry
in the electronic circuit causes the flow control valve in GFC 17
to be opened for a predetermined time and allow a predetermined
amount of the enriched gas in the mixing tank 15 to be delivered to
the user through the outlet. Depending on training and/or
therapeutic levels required, the amount, concentration and timing
of the delivered product gas is controlled by the electronic
circuit using a programmable device for delivery of any one of a
number of selectable effective flow rates and nitrogen
concentrations, the settings for which may be made by a multiple
position control switch.
In the second embodiment as shown in FIG. 3, the PSA/GFC may be
switched from producing a high nitrogen concentration gas to one
producing a high oxygen concentration product gas. In the
embodiment shown in FIG. 3, the adsorbant sieve material is a
conventional nitrogen adsorbing material, in which oxygen enriched
gas is produced using the principles as described in co-pending
U.S. application Ser. No. 09/851,750, now U.S. Pat. No. 6,558,451,
issued May 6, 2003 and co-pending applications Ser. No. 60/353,563
and Ser. No. 10/354,275. When the apparatus is selected to produce
a nitrogen enriched gas, a selector switch (not shown)
simultaneously opens both valves 26 to exhaust the oxygen
concentrated gas to the atmosphere and closes both valves 25 to
cause the purged nitrogen gas to be delivered to the GFC 23 through
its mixing tank 16, pressure regulator 18, flow restrictor 19 and
flowmeter 22. On the other hand, if an oxygen enriched gas is
desired, both valves 26 are closed and both valves 25 opened to
exhaust the adsorbed nitrogen gas while causing the oxygen
concentrated gas to be delivered to the GFC 21 through its
corresponding mixing tank 16, its pressure regulator 18, flow
restrictor 19 and flowmeter 20. As the flow rates and
concentrations of the nitrogen and the oxygen concentrated gas when
delivered to the user will differ, each is controlled by its own
GFC timed to operate differently by the selector switches. The
settings for delivering the oxygen concentrated gas may be scaled
by effective oxygen concentrations, whereas the nitrogen delivery
may be scaled by equivalent geographic altitudes. Suitable
electronics to initiate and time flow can be made by those skilled
in the art, referring for example, to the device shown in U.S. Pat.
No. 6,427,690.
A variation of the second embodiment is shown in FIG. 3A, in which
it is possible to incorporate the electronics of both of the GFCs
into a single device with appropriate switch controls that could,
for example, interchange the readable gas delivery scales when the
function switch is changed between concentrated oxygen and
concentrated nitrogen.
As with FIG. 2, FIGS. 4 and 5 illustrate the flow diagrams for the
embodiment of FIGS. 3 and 3A, with the sequence and an example of
timing of valves indicated according to whether a nitrogen enriched
gas (FIG. 4) or an oxygen enriched gas (FIG. 5) is to be delivered
to the user. It will be appreciated that the timing and operating
parameters may be varied based on size of the components and the
materials used.
Although the apparatus according to our invention is shown by two
preferred embodiments, those skilled in the art will be able, from
the description of our invention as herein provided, to produce a
combined PSA/GFC apparatus, the individual fluid, electric and
electronic components and controls of which can be found in the art
or made by one skilled in the art following a reading of this
description of the preferred embodiment. For portability, the
apparatus may be made to be comparable in size and powered as in
the LIFESTYLE.TM. Portable Oxygen Concentrator currently marketed
by AirSep Corporation of Buffalo, N.Y. It is possible to use a
three bed PSA as described in U.S. Pat. No. 6,558,451, the entire
disclosure of which also is incorporated by reference herein, the
use of which may not require a mixing tank because of the
relatively constant output pressure achieved by a PSA made
according to that invention. It also is possible to include a known
gas monitor to measure the actual rather than the calculated
concentration of the selected product gas being delivered to the
user. In addition, those skilled in the art may be able to include
other known monitor and/or safety features for use in monitored
and/or unmonitored physical training or medical purposes, such as
alarms to warn of excessive breathing rates causing "overdraw", a
meter measuring use of the apparatus between servicing, a washable
filter at the gas delivery outlet, and a test sequence circuit to
ensure proper functioning of the apparatus.
To operate the apparatus the user accessible selector switch is
turned to the desired "equivalent" flow rate on the operating panel
both to turn on the PSA operation and to deliver nitrogen or oxygen
enriched gas at the set altitude or rate. At start-up of the
apparatus, all of valves are open to eliminate any back pressure
and then either left open or closed in sequence through a timing
mechanism of conventional switches and relay switches in the
programmable circuit. As each of the feed, waste, and equalization
valves is preferably a solenoid-type valve responsive to a turning
on or shutting off of power to the valve, product-producing and
regeneration operations are automatically controlled in the
apparatus 20 by automatically controlling the amount of time that
each of the feed, waste, and equalization valves are opened and
closed.
The apparatus can be powered any one of three sources, including a
rechargeable battery pack for active physical training, an AC
adapter to connect the apparatus to an AC outlet for both rest
periods and when using stationary training devices such as a
treadmill, and a "cigarette lighter" adapter for a similar
connection to an automobile type battery in a training vehicle. The
circuit can be designed so that both the AC adapter and the
automobile type battery can power the apparatus and recharge the
battery pack simultaneously.
It will be understood that various modifications and substitutions
may be made to the described embodiment without departing from the
spirit of the invention. Accordingly, the described preferred
embodiment is intended for purposes of illustration and not as a
limitation.
* * * * *
References